feathersjs socket handler allows abusing implicit toString

Feathersjs is a framework for creating web APIs and real-time applications with TypeScript or JavaScript. Feathers socket handler did not catch invalid string conversion errors like `const message = ${{ toString: '' }}` which would cause the NodeJS process to crash when sending an unexpected Socket.io message like `socket.emit('find', { toString: '' })`. A fix has been released in versions 5.0.8 and 4.5.18. Users are advised to upgrade. There is no known workaround for this vulnerability.